const path = require("path");
const resolve = dir => path.join(__dirname, dir);
// const IS_PROD = ["production", "prod"].includes(process.env.NODE_ENV);
module.exports = {
  // 所有的资源都会被链接为相对路径, 此属性相当于2.x中的 assetsPublicPath,域名后的第一个目录名称
  publicPath: "/",

  // 生产环境构建文件的目录
  outputDir: "dist",

  // 放置生成的静态资源 (js、css、img、fonts) 的 (相对于 outputDir 的) 目录。
  assetsDir: "static",

  // 是否在开发环境下通过 eslint-loader 在每次保存时 lint 代码。
  // 这个值会在 @vue/cli-plugin-eslint 被安装之后生效
  lintOnSave: false,

  // 如果你不需要生产环境的 source map，可以将其设置为 false 以加速生产环境构建。
  productionSourceMap: false,
  // 所有 webpack-dev-server 的选项
  devServer: {
    port: process.env.port || 9527,

    //   dev-server在服务器启动后打开默认浏览器
    open: true,

    // 出现编译器错误或警告时，在浏览器中显示全屏覆盖。
    overlay: {
      warnings: true,
      errors: true
    },

    //   proxy对象存在时，对象里面不能为空
    proxy: {
      "/wx/": {
        target: "http://192.168.1.133:10000/",
        changeOrigin: true,
        pathRewrite: {
          "^/wx": "/wx"
        }
      }
    }
  },
  configureWebpack: {
    resolve: {
      // <!--设置别名-->
      alias: {
        "@": resolve("src")
      }
    }
  },
  chainWebpack(config) {
    config.plugins.delete("preload"); // TODO: need test
    config.plugins.delete("prefetch"); // TODO: need test

    // set svg-sprite-loader
    config.module
      .rule("svg")
      .exclude.add(resolve("src/icons"))
      .end();
    config.module
      .rule("icons")
      .test(/\.svg$/)
      .include.add(resolve("src/icons"))
      .end()
      .use("svg-sprite-loader")
      .loader("svg-sprite-loader")
      .options({
        symbolId: "icon-[name]"
      })
      .end();

    // set preserveWhitespace
    config.module
      .rule("vue")
      .use("vue-loader")
      .loader("vue-loader")
      .tap(options => {
        options.compilerOptions.preserveWhitespace = true;
        return options;
      })
      .end();

    config
      // https://webpack.js.org/configuration/devtool/#development
      .when(process.env.NODE_ENV === "development", config =>
        config.devtool("cheap-source-map")
      );

    config.when(process.env.NODE_ENV !== "development", config => {
      config
        .plugin("ScriptExtHtmlWebpackPlugin")
        .after("html")
        .use("script-ext-html-webpack-plugin", [
          {
            // `runtime` must same as runtimeChunk name. default is `runtime`
            inline: /runtime\..*\.js$/
          }
        ])
        .end();
      config.optimization.splitChunks({
        chunks: "all",
        cacheGroups: {
          libs: {
            name: "chunk-libs",
            test: /[\\/]node_modules[\\/]/,
            priority: 10,
            chunks: "initial" // only package third parties that are initially dependent
          },
          elementUI: {
            name: "chunk-elementUI", // split elementUI into a single package
            priority: 20, // the weight needs to be larger than libs and app or it will be packaged into libs or app
            test: /[\\/]node_modules[\\/]_?element-ui(.*)/ // in order to adapt to cnpm
          },
          commons: {
            name: "chunk-commons",
            test: resolve("src/components"), // can customize your rules
            minChunks: 3, //  minimum common number
            priority: 5,
            reuseExistingChunk: true
          }
        }
      });
      config.optimization.runtimeChunk("single");
    });
  }
};
